Sequencing of DNA and RNA has become a routine tool in cell biology, immunology and cancer research over the past ten years. For all of this period, there has been a sequencing facility at Fox Chase supported by our Cancer Center Core Grant. This grant provides limited support (technician and modest amount for supplies). Charge-backs recover the rest of the supply costs. No funding is available for equipment. The Facility has served to train various members of FCCC to use the Maxam-Gilbert and the dideoxy DNA sequencing methods. It has provided ready access to reagents and equipment (power supplies, gel apparatus, gel processing apparatus), particularly helpful to labs just starting sequencing programs or with only limited demands. It has also carried out manual sequencing (both RNA and DNA) for several groups, although most labs with extensive demands for sequencing have chosen to carry this out on their own. Major reasons for this choice have been slow turn-around time due to limited throughput or perceived lack of any real advantage over in-lab sequencing. In the past five years, automated sequencing has reached maturity. Initial instruments, software and chemistries all carried limitations that made this type of analysis unreliable: often sequences were obtained only with extremely purified DNA and even then accuracy was typically <95% necessitating "hands-on" correction and proofreading. These limitations have been largely overcome in the current generation of instrument which utilizes up to four different chemistries (depending on application) and which routinely yields 400-500 base sequences at 98.5% or greater accuracy. Therefore, the acquisition of such an instrument would greatly enhance the utility of this facility to the Fox Chase community. In order to justify the purchase of this instrument, we have provided a brief summary of the programs of the major sequence users at Fox Chase, together with specific applications of sequencing and several recent publications, as well as their peer review funding. This group represents approximately 90% of the planned usage.